Index: lib/CodeGen/SelectionDAG/InstrEmitter.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/InstrEmitter.cpp
+++ lib/CodeGen/SelectionDAG/InstrEmitter.cpp
@@ -315,6 +315,30 @@
                                  const MCInstrDesc *II,
                                  DenseMap<SDValue, unsigned> &VRBaseMap,
                                  bool IsDebug, bool IsClone, bool IsCloned) {
+  if (RegisterSDNode *R = dyn_cast<RegisterSDNode>(Op)) {
+    // Turn additional physreg operands into implicit uses on non-variadic
+    // instructions. This is used by call and return instructions passing
+    // arguments in registers.
+    unsigned VReg = R->getReg();
+    MVT OpVT = Op.getSimpleValueType();
+    const TargetRegisterClass *OpRC =
+        TLI->isTypeLegal(OpVT) ? TLI->getRegClassFor(OpVT) : nullptr;
+    const TargetRegisterClass *IIRC =
+        II ? TRI->getAllocatableClass(TII->getRegClass(*II, IIOpNum, TRI, *MF))
+           : nullptr;
+
+    if(OpRC && IIRC && OpRC != IIRC &&
+       TargetRegisterInfo::isVirtualRegister(VReg)) {
+      unsigned NewVReg = MRI->createVirtualRegister(IIRC);
+      BuildMI(*MBB, InsertPos, Op.getNode()->getDebugLoc(),
+               TII->get(TargetOpcode::COPY), NewVReg).addReg(VReg);
+      VReg = NewVReg;
+    }
+    bool Imp = II && (IIOpNum >= II->getNumOperands() && !II->isVariadic());
+    MIB.addReg(VReg, getImplRegState(Imp));
+    return;
+  }
+
   assert(Op.getValueType() != MVT::Other &&
          Op.getValueType() != MVT::Glue &&
          "Chain and glue operands should occur at end of operand list!");
@@ -386,19 +410,13 @@
                               const MCInstrDesc *II,
                               DenseMap<SDValue, unsigned> &VRBaseMap,
                               bool IsDebug, bool IsClone, bool IsCloned) {
-  if (Op.isMachineOpcode()) {
+  if (Op.isMachineOpcode() || dyn_cast<RegisterSDNode>(Op)) {
     AddRegisterOperand(MIB, Op, IIOpNum, II, VRBaseMap,
                        IsDebug, IsClone, IsCloned);
   } else if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
     MIB.addImm(C->getSExtValue());
   } else if (ConstantFPSDNode *F = dyn_cast<ConstantFPSDNode>(Op)) {
     MIB.addFPImm(F->getConstantFPValue());
-  } else if (RegisterSDNode *R = dyn_cast<RegisterSDNode>(Op)) {
-    // Turn additional physreg operands into implicit uses on non-variadic
-    // instructions. This is used by call and return instructions passing
-    // arguments in registers.
-    bool Imp = II && (IIOpNum >= II->getNumOperands() && !II->isVariadic());
-    MIB.addReg(R->getReg(), getImplRegState(Imp));
   } else if (RegisterMaskSDNode *RM = dyn_cast<RegisterMaskSDNode>(Op)) {
     MIB.addRegMask(RM->getRegMask());
   } else if (GlobalAddressSDNode *TGA = dyn_cast<GlobalAddressSDNode>(Op)) {
Index: test/CodeGen/Mips/tailcall/tailcall.ll
===================================================================
--- test/CodeGen/Mips/tailcall/tailcall.ll
+++ test/CodeGen/Mips/tailcall/tailcall.ll
@@ -10,23 +10,23 @@
 ; RUN:      -verify-machineinstrs -mips-tail-calls=1 < %s | \
 ; RUN:     FileCheck %s -check-prefixes=ALL,PIC16
 
-; RUN: llc -march=mipsel -relocation-model=pic -mattr=+micromips -mips-tail-calls=1 < %s | \
-; RUN:     FileCheck %s -check-prefixes=ALL,PIC32MM
-; RUN: llc -march=mipsel -relocation-model=static -mattr=+micromips \
+; RUN: llc -march=mipsel -relocation-model=pic -mattr=+micromips -verify-machineinstrs \
+; RUN:     -mips-tail-calls=1 < %s | FileCheck %s -check-prefixes=ALL,PIC32MM
+; RUN: llc -march=mipsel -relocation-model=static -mattr=+micromips -verify-machineinstrs \
 ; RUN:     -mips-tail-calls=1 < %s | FileCheck %s -check-prefixes=ALL,STATIC32
 
-; RUN: llc -march=mipsel -relocation-model=pic -mcpu=mips32r6 -mips-tail-calls=1 < %s | \
-; RUN:     FileCheck %s -check-prefixes=ALL,PIC32R6
-; RUN: llc -march=mipsel -relocation-model=static -mcpu=mips32r2 \
+; RUN: llc -march=mipsel -relocation-model=pic -mcpu=mips32r6 -verify-machineinstrs \
+; RUN:     -mips-tail-calls=1 < %s | FileCheck %s -check-prefixes=ALL,PIC32R6
+; RUN: llc -march=mipsel -relocation-model=static -mcpu=mips32r2 -verify-machineinstrs \
 ; RUN:     -mips-tail-calls=1 < %s | FileCheck %s -check-prefixes=ALL,STATIC32
-; RUN: llc -march=mips64el -relocation-model=pic -mcpu=mips64r2  \
+; RUN: llc -march=mips64el -relocation-model=pic -mcpu=mips64r2 -verify-machineinstrs \
 ; RUN:     -mips-tail-calls=1 < %s | FileCheck %s -check-prefix=PIC64
-; RUN: llc -march=mips64el -relocation-model=pic -mcpu=mips64r6  \
+; RUN: llc -march=mips64el -relocation-model=pic -mcpu=mips64r6 -verify-machineinstrs \
 ; RUN:     -mips-tail-calls=1 < %s | FileCheck %s -check-prefix=STATIC64
 
-; RUN: llc -march=mipsel -relocation-model=pic -mcpu=mips32r6 -mattr=+micromips \
+; RUN: llc -march=mipsel -relocation-model=pic -mcpu=mips32r6 -mattr=+micromips -verify-machineinstrs \
 ; RUN:      -mips-tail-calls=1 < %s | FileCheck %s -check-prefixes=ALL,PIC32MM
-; RUN: llc -march=mipsel -relocation-model=static -mcpu=mips32r6 \
+; RUN: llc -march=mipsel -relocation-model=static -mcpu=mips32r6 -verify-machineinstrs \
 ; RUN:     -mattr=+micromips -mips-tail-calls=1 < %s | FileCheck %s -check-prefixes=ALL,STATIC32MMR6
 
 @g0 = common global i32 0, align 4